Post on 08-Jul-2015
transcript
Input and OutputGina 10A
Input
Input devices allow us to enter raw data into a computer.
The computer processes the data and then produces
outputs that we can understand using an output device.
The processing is mainly handled by the CPU.
2 types of Input:
Manual
Automatic
Manual Input Devices
Keyboard
Made up of buttons, “Keys”.
“QWERTY” is another word for keyboard. Come from the first 6 letters on the top row of the alphabet keys.
Alphanumeric Keyboard
Allows:
text (abc…)
number (123…)
Symbols (@#$...)
Numeric Keypad
Small keyboard
Only have numbers
Enter numeric data into ATM
PIN Pad
Enter Personal Identity Number (PIN)
Electronic door locks.
Mouse
Pointing device
Sensors on the bottom of the mouse detect when the mouse is moved.
Optical or wireless technology to track mouse movement.
control by GUI
Touchpad/Trackpad
On laptops
Take up less space
Use by fingers
Control by GUI
Trackball/Tracker Ball
Pointing device
Large ball that user spins.
Control by GUI pointer
Limited movement (disabled)
Very young, easier to use than a mouse
Touch screen
Touching the surface
Very intuitive and simple to use.
Information terminals in public places e.g museums.
Graphics Tablet
Pointing device
Used by designers and artists.
Allows natural hand movements.
Input to graphicsapplication.
Hand-drawn sketches
Joystick/ Joypad
Playing games
Small joysticks can be found on some mobile phones.
Light Pen
Pointing device
Write on screen
Rarely used
Scanner
Scans images, etc.
Taking close-up photograph
Most common scanner is Flat-bed.
Digital Camera
Digital photographs
Store on memory cards.
Transferred to a computer.
10 Megapixels
Video Camera
Stored on video-tape or memory cards.
Later transferred to a computer.
Television production
Web Cam
Very basic video camera
Live video into computer
Low quality
For web chats
Microphone
Converts sound into a signal
Analogue
ADC: Analogue Digital Convertor
Automatic Input Devices
Magnetic Strip Reader
Strip of material that can be magnetised on the back.
Data stored in the form of magnetised dots.
Data stored on the strip
Data shown on the front of the card.
Faster and more accurately
Swiping the card through a slot.
Smart Card/Chip Reader
Chip of computer memory
Smart cards
Data stored in this memory and read back using a chip reader.
Connect to metal pads
The reader can access the memory chip and data stored.
MICR Reader
Magnetic Ink Character Recognition
Bank cheques
Quickly & accurately
Cheque number & bank account number are printed at the bottom of the bank cheque.
Special magnetic Ink, special front
MICR reader
OMR Scanner
Optical Mark Recognition
read quickly & accurately
Special OMR forms can be coloured in.
Marks then detected by OMR scanner.
Multiple-choice exam answer sheets & lottery number forms.
OCR Scanner
Optical Character recognition
Convert images of text into an actual text file
Scanned, scanned image then analysed by OCR software.
Letter shapes
handwriting or handwriting recognition
Barcode Reader/Scanner
Numeric code
Series of lines
Barcode reader/scanner
Point-of-Scale (POS)
Code
Read barcode, quick & accurate than typing.
Sensors
Senses (5 senses)
Converts a real-world property into data that computer can process.
Analogue signal converted into digital data for computer.
Analogue-to-Digital-Converter (ADC)
Use: monitoring, measuring, data logging systems & computer control systems.
Remote Control
Send data signal by button.
Infrared light or radio signals
Control a computer from some distance.
Control a presentation slideshow.
Output
CRT Monitor
Displays text & image
Cathode-ray tube (CRT)
Large & boxy
A lot of desk space.
Replaced by flat-screen monitors.
Accuracy & brightness
Flat-Screen Monitor (TFT or
LCD)
Replaced CRT monitors
Light in weight
Little desk space
Picture quality
Digital/Multimedia Projector
Very large viewing area e.g.: presentations for advertising or watching movies.
DVD player
Satellite receiver
Powerful light source
Loudspeaker
Music or sounds
Convert electrical signals into sound waves
Music editing, video conferencing, watching movie.
Dot Matrix Printer
Tiny pins
Leaves a pattern of dots. Can form letters, images, etc.
Continuous stationary
Quality is poor
Noisy
Carbon-copies e.g. airline tickets
Duplicate pages all printed in one go.
Very cheap
Last for a long time e.g. shop receipts.
InkJet Printer
Cheap, High-quality
Full-colour
Squirts tiny droplets
Full-colour
Tiny holes: jets
Perfect for photographs
Very quite
Cheap to manufacture
Ink is very expensive
Expensive to use
Laser Printer
Very complex
Expensive to buy
Very cheap to use
Marks on paper >> toner
Complex system, laser
Very fast printing
Very common use in offices
Plotter
Draw on paper using a pen
Accurately & quickly
Different coloured pens
Used by designers & architects
Huge pieces of paper
Motor
Movement
In washing machine, microwave & air conditioning units.
Switched on & off
Pumps
Push water
Air along pipes
Part of watering systemsin greenhouses, in factories.
Buzzer
Provide noise
In microwave oven
Louder noise in siren or electric bell, e.g. burger alarm system.
Lights
Light bulbs
LEDs
Provide lights or indicate something.
E.g. traffic lights, in car dashboards
Heater/Cooler
Provide heat
Cool things down
Keep a room or a greenhouse at correct temperature.
Cooling unit
Keep food fresh